/**
 * BibSonomy-Scraper - Web page scrapers returning BibTeX for BibSonomy.
 *
 * Copyright (C) 2006 - 2016 Knowledge & Data Engineering Group,
 *                               University of Kassel, Germany
 *                               http://www.kde.cs.uni-kassel.de/
 *                           Data Mining and Information Retrieval Group,
 *                               University of Würzburg, Germany
 *                               http://www.is.informatik.uni-wuerzburg.de/en/dmir/
 *                           L3S Research Center,
 *                               Leibniz University Hannover, Germany
 *                               http://www.l3s.de/
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.bibsonomy.scraper.url.kde.citeseer;

import java.util.Collections;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.bibsonomy.common.Pair;
import org.bibsonomy.scraper.AbstractUrlScraper;
import org.bibsonomy.scraper.ScrapingContext;
import org.bibsonomy.scraper.exceptions.PageNotSupportedException;
import org.bibsonomy.scraper.exceptions.ScrapingException;


/**
 * Scraper for CiteSeer
 * 
 * @author rja
 */
public class CiteseerBasicScraper extends AbstractUrlScraper {

	private static final String SITE_NAME = "CiteSeer";

	private static final String CITE_URL = "http://citeseer.ist.psu.edu/";

	private static final String info = "This scraper parses a publication page from the " +
	"Scientific Literature Digital Library " + href(CITE_URL, SITE_NAME)+".";

	private static final String  CS_HOST_NAME   = "citeseer.ist.psu.edu";
	private static final Pattern bibPattern = Pattern.compile(".*<pre>\\s*(@[A-Za-z]+\\s*\\{.+?\\})\\s*</pre>.*", Pattern.MULTILINE | Pattern.DOTALL);
	
	private static final List<Pair<Pattern, Pattern>> patterns = Collections.singletonList(new Pair<Pattern, Pattern>(Pattern.compile(".*" + CS_HOST_NAME), AbstractUrlScraper.EMPTY_PATTERN));
	
	@Override
	protected boolean scrapeInternal(ScrapingContext sc) throws ScrapingException{
		sc.setScraper(this);
		
		final Matcher m = bibPattern.matcher(sc.getPageContent());	
		if (m.matches()) {
			sc.setBibtexResult(m.group(1));
			return true;
		}
		
		throw new PageNotSupportedException("no bibtex snippet available");
	}

	@Override
	public String getInfo() {
		return info;
	}

	@Override
	public List<Pair<Pattern, Pattern>> getUrlPatterns() {
		return patterns;
	}

	@Override
	public String getSupportedSiteName() {
		return SITE_NAME;
	}

	@Override
	public String getSupportedSiteURL() {
		return CITE_URL;
	}
}
